State of Louisiana offers an income tax credit worth 50% of the cost of PHEV Conversion

Alternative Fuel Vehicle (AFV) and Fueling Infrastructure Tax Credit
The state offers an income tax credit worth 50% of the cost of converting a vehicle to operate on an alternative fuel, 50% of the incremental cost of purchasing an original equipment manufacturer AFV, and 50% of the cost of constructing an alternative fueling station. Only vehicles registered in Louisiana may receive the tax credit. Alternatively, a taxpayer may take a tax credit worth 10% of the cost of the motor vehicle or up to $3,000, whichever is less. For the purpose of this incentive, alternative fuels include compressed natural gas, liquefied natural gas, liquefied petroleum gas/propane, biofuel, biodiesel, methanol, ethanol, electricity, and any other fuels that meet or exceed federal clean air standards. (Reference Louisiana Revised Statutes 47:6035)